Moving coil relay



July 14, 1959 I w, OTINE 2,895,030

' MOVING c011. RELAY Filed April 9, 1956 2 Sheets-Sheet; 1

INVENTXOR. WILLIAM HOTINE ATTQRNEY July 14, 1959 w. OWE 2,895,030

MOVING C OIL RELAY Filed April 9, 1956 2 Sheets-Sheet 2 INVENTOR. WILLIAM HOTINE ATTORNEY United States Patent MOVING COIL v RELAY William Hotine, Beaumont, Calif. ApplicationApril 9, 1956, Serial No. 577,121 2 Claims. (Cl. 200-110) Thislinvention relates to amoving; coil relayhaving exceptional sensitivity; It hasparticular reference to the design and construction of a resilient mounting for the contact points v ofthe relay.

Previous designs of moving coil relays have-required complicated assembly procedures. This has been due, mainly,- to the fact, that moving coil relays were based upon similar type measuring instruments having a pointer and'scale. In general, moving coil DArsonval movements require close concentricity between the core magnet,;the moving coil, and the surrounding cylindrical magnetic yoke. The present design comprises a novel assembly means, for arranging a central core magnet, a moving. coil, and an outer yoke with a minimum of adjustment.

One of the objects of-this invention is to provide-an improved moving coilrelaywhich avoids one or more of the disadvantages and limitations of prior art arrangements.

Another object of the invention is to simplify the construction of sensitive relay mechanisms.

Another object of the invention is to increase the ease of assembly of sensitive relays.

Another object of the invention is to provide amov-ing coil relay having high efiicieney and sensitivity.

Another object of' the invention is to provide; improved contact members in a sensitive relay assembly which possess resiliency and produce a wiping action when contact, is made.

Another object of the invention is to provide an integral shock mounting for the entire relay assembly.

The invention comprises a moving coil relay which includes a permanent'm'agnet having a cylindrical shape, acting as the core of the instrument. A moving coil is pivotally mounted so as to surround the core and move through magnetic lines of force in a magnetic field produced by the core. A supporting frame includes pivot means for supporting the moving coil and a relay contact structure is mounted on the coil, moving with the coil and adapted to make contact with a second relay contact structure mounted on the frame. The relay contact structure mounted on the coil includes a torsional spring member Which resiliently flexes when the two contacts touch each other.

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.

Fig. 1 is an isometric view of the relay container, showing the contact pins for external connection.

Fig. 2 is a partial cross sectional view showing the container in section and the relay in elevation.

Fig. 3 is a cross sectional view of the relay shown in Fig. 2, taken along line 3-3 of that figure.

Fig. 4 is a cross sectional view of parts of the relay system, showing the magnetic core, the frame, and

2,895,030 Patented July 14, 1959 "ice the cylindrical yokemounted in the container, and sup portedresiliently'by the integral ring-type shock mount.

Fig. 5 is a top view of the relay assembly showing the frame, the pivot assembly, the relay contacts, and the moving coil.

Fig. 6 is an isometric view of the relay contacts and their associatedsupportingstructure, somewhat enlarged.

Fig. 7 is a cross sectional view, somewhat enlarged, showing the details of one end of the relay. This view shows the pivot, the hair spring, the. contact mounting'arrangements, and the moving coil.

Fig. 8-is a top view of a portionof the relayillus tratinghow three pairs of contacts may be incorporated in the relay assembly.

Referring now to the drawings, a container 10 houses thecomplete relay assembly and includes a base section 11, a cylindrical section 12, and an insulator disk 13. Connector pins 14 are moulded'in the insulator disk and serve as connecting means for external circuits.

The relay assembly includes an external shell 15 which is made of'soft iron and provides a return path for the magnetic flux produced by a permanent magnet core 23 (see Figs. 3, 4, and 5). The shell 15 is formed with two slots 16 and 17 on itsexterior surface and two resilient 0 rings 18 and 20 are positioned in the slots and act as a shock absorber means to retain the relay assembly within the container 10.

The rotating portion of the relay is mounted on a nonmagnetic frame 21 which comprises a U-shaped piece of brass or other non-magnetic material provided With a dove-tailed portion 21A. The dove-tailed portionfits into a slot in the shell 15 -and is held by staking. Mid-way between the two turned-over portions of the frame a non-magnetic web 22 is soldered to, and supports, the permanent magnet 23. The permanent magnet is cylindrical in shape and is magnetized with a north and south pole as indicated in Fig. 3, forming magnetic flux lines which traverse the gap between the permanent magnet core 23-andthe shell 15. The shell 15 is formed with two dove-tailed slots. opposite eachother, onefor the frame and the other forone or more conductors24 which may be positioned? parallel to the shell axisrunning from one pivot assembly to the other. A shield 25 may be employed to protect. these conductors and retain them in the slot to avoid contact with the moving coil 38.

The details of the pivot assembly and the relay contacts are shown in Fig. 7 where a central pivot screw 26 contains a jeweled bearing 27 at its lower extremity and includes .a long threaded portion which is screwed into the turned-over portion of frame 21. A lock nut 28 is assembled on the upper end of screw 26 so as to retain it in its adjusted position. On the outside of the lock nut surface an insulating sleeve 30 is positioned and insulates the conductive washer portions of one of the contact structures 31 and one terminal 32 of a hair spring support. These washer portions are insulated from each other and from the frame 21 by three insulating washers 33, 34, and 35, all closely fitted over the outside surface of sleeve 30. The washers are re siliently retained in their operating position by a spring washer 36. Contact 31 may be rotated to adjust its angular position with relation to contact 57, and will remain at this point due to friction of washers 33 and 34.

The gap between the magnet core 23 and shell 15 contains a coil support 37 on which is wound a plurality of turns of fine wire 38 comprising the operating winding of the relay. A pivot block 40 is secured to the winding 38 by plastic cement and includes a cylindrical extension 41 which holds a pivot rod 42 and a series 2,895,030 I I y ofinsulator disks 4s, 44, and 45. Between disks 44 and 45 a conductive terminal washer 46 is mounted and between insulators 43 and 44 a conductive contact assembly 47 is secured. Details of the two contact assemblies are shown in Fig. 6. One end of washer 46 is connected to one of the wires from winding 38 while its other end is secured to a spiral hair spring 48. The Washer assembly may be held in place by a metallic member 50 which is used only as a means of balancing the rotating assembly. A coil 51, movable along the end of member 50' is for adjustably maintaining this balance. The other end of hair spring 48 is secured to terminal 32; the terminal, hair spring, and washer 46 providing a means for conducting current into coil 38.

The details of the contact assembly are shown in 6 where the stationary washer 31 acts as a support-for a flat metallic conductor 52 generally made of platinumiridium to insure absence of corrosion and low contact resistance. port 53 which contains a spring wire 54 soldered at one end to a terminal lug 55 and containing a contact wire 56 soldered to its free end. Wire 54 has suflicient torsional elasticity to provide a resilient mounting for contact wire 56 when it is moved into engagement with contact plate 52. The upper end of contact wire 56 is formed with a curved portion 57. so that a wiping action is provided when the two contacts touch each other.

Fig. 7 shows only one end of the moving coil arrangement, the other end being similar but omitting the contact members 56 and 52 and their associated washers 31 and 47. It will be obvious that the other end of the coil assembly will include a pivot block and a terminal for the other end of the winding, also a hair spring similar to spring 48 and a terminal wire 32.

The present invention is not limited to a single pair of contacts. A second pair of contacts may be mounted on the other end of the coil, in which case both ends will have a similar construction. In the event that a larger number of contact pairs are desired, a number of them may be mounted at one end of the coil assembly as indicated in Fig. 8 where three contact pairs 60, 61, and 62, are mounted approximately 120 degrees apart. It will be obvious that adjustments can be easily made so that one pair of contacts may touch in advance of another pair, the torsional resiliency of the moving contact mounting permitting this construction.

' Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States, is:

' 1. A moving coil relay comprising, a permanent mag- Washer assembly. 47 includes anangle sup- I 4 a. net core having a cylindrical shape, a coil surrounding said core and pivotally mounted to move through magnetic lines in a magnetic field produced by said core, a paramagnetic shell surrounding said coil which provides a return path for said magnetic lines, a non-magnetic frame which includes pivot means for supporting said coil, a first relay contact structure mounted on the frame, and a second relay contact structure mounted on the coil and adapted to touch the first contact structure when the coil is rotated, said second contact structure including a torsional spring member on said coil, secured at its inner end and laterally supported for resiliently flexing when the first and second contact structures touch, a supporting bracket member having an L shaped cross section secured at one end to the coil and extending laterally along substantially the entire length of the spring member.

2. A moving coil relay comprising, a permanent magnet core having a cylindrical shape, a coil surrounding said core and pivotally mounted to move-through magnetic lines in a magnetic field produced by said core, a paramagnetic shell surrounding said coil which pro vides a return path for said magnetic lines, said paramagnetic shell being formed with two slots on its exterior surface, a resilient ring mounted in each of the said slots, a hermetically sealed container around the shell, shoulders formed on the inner surface of the container, said shell being mounted within the container by means of the resilient rings clamped between the said shoulders, a non-magnetic frame which includes pivot means for supporting said coil, a first-relay contact structure mounted on the frame, and a second relay contact structure mounted on the coil and adapted to touch the first contact structure when the coil is rotated, said second contact structure including a torsional spring member on said coil secured at its inner end and laterally supported for resiliently flexing when the first and second contact structures touch.

References Cited in the file of this patent UNITED STATES PATENTS 786,696 Vreeland Apr. 4, 1905 1,920,764 Nickle Aug. 1, 1933 2,324,265 McMaster July 13, 1943 2,353,616 Lamb July 11, 1944 2,668,208 Lamb et al. Feb. 2, 1954 2,717,297 Walker Sept. 6, 1955 FOREIGN PATENTS 139,476 Great Britain Nov. 4, 1920 

